/* * DECnet An implementation of the DECnet protocol suite for the LINUX * operating system. DECnet is implemented using the BSD Socket * interface as the means of communication with the user level. * * DECnet Routing Forwarding Information Base (Routing Tables) * * Author: Steve Whitehouse <SteveW@ACM.org> * Mostly copied from the IPv4 routing code * * * Changes: * */ #include <linux/config.h> #include <linux/string.h> #include <linux/net.h> #include <linux/socket.h> #include <linux/sockios.h> #include <linux/init.h> #include <linux/skbuff.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> #include <linux/proc_fs.h> #include <linux/netdevice.h> #include <linux/timer.h> #include <linux/spinlock.h> #include <asm/atomic.h> #include <asm/uaccess.h> #include <linux/route.h> /* RTF_xxx */ #include <net/neighbour.h> #include <net/dst.h> #include <net/flow.h> #include <net/dn.h> #include <net/dn_route.h> #include <net/dn_fib.h> #include <net/dn_neigh.h> #include <net/dn_dev.h> struct dn_zone { struct dn_zone *dz_next; struct dn_fib_node **dz_hash; int dz_nent; int dz_divisor; u32 dz_hashmask; #define DZ_HASHMASK(dz) ((dz)->dz_hashmask) int dz_order; __le16 dz_mask; #define DZ_MASK(dz) ((dz)->dz_mask) }; struct dn_hash { struct dn_zone *dh_zones[17]; struct dn_zone *dh_zone_list; }; #define dz_key_0(key) ((key).datum = 0) #define dz_prefix(key,dz) ((key).datum) #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\ for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) #define endfor_nexthops(fi) } #define DN_MAX_DIVISOR 1024 #define DN_S_ZOMBIE 1 #define DN_S_ACCESSED 2 #define DN_FIB_SCAN(f, fp) \ for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next) #define DN_FIB_SCAN_KEY(f, fp, key) \ for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next) #define RT_TABLE_MIN 1 static DEFINE_RWLOCK(dn_fib_tables_lock); struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1]; static kmem_cache_t *dn_hash_kmem __read_mostly; static int dn_fib_hash_zombies; static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz) { u16 h = dn_ntohs(key.datum)>>(16 - dz->dz_order); h ^= (h >> 10); h ^= (h >> 6); h &= DZ_HASHMASK(dz); return *(dn_fib_idx_t *)&h; } static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz) { dn_fib_key_t k; k.datum = dst & DZ_MASK(dz); return k; } static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz) { return &dz->dz_hash[dn_hash(key, dz).datum]; } static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz) { return dz->dz_hash[dn_hash(key, dz).datum]; } static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b) { return a.datum == b.datum; } static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b) { return a.datum <= b.datum; } static inline void dn_rebuild_zone(struct dn_zone *dz, struct dn_fib_node **old_ht, int old_divisor) { int i; struct dn_fib_node *f, **fp, *next; for(i = 0; i < old_divisor; i++) { for(f = old_ht[i]; f; f = f->fn_next) { next = f->fn_next; for(fp = dn_chain_p(f->fn_key, dz); *fp && dn_key_leq((*fp)->fn_key, f->fn_key); fp = &(*fp)->fn_next) /* NOTHING */; f->fn_next = *fp; *fp = f; } } } static void dn_rehash_zone(struct dn_zone *dz) { struct dn_fib_node **ht, **old_ht; int old_divisor, new_divisor; u32 new_hashmask; old_divisor = dz->dz_divisor; switch(old_divisor) { case 16: new_divisor = 256; new_hashmask = 0xFF; break; default: printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor); case 256: new_divisor = 1024; new_hashmask = 0x3FF; break; } ht = kmalloc(new_divisor*sizeof(struct dn_fib_node*), GFP_KERNEL); if (ht == NULL) return; memset(ht, 0, new_divisor*sizeof(struct dn_fib_node *)); write_lock_bh(&dn_fib_tables_lock); old_ht = dz->dz_hash; dz->dz_hash = ht; dz->dz_hashmask = new_hashmask; dz->dz_divisor = new_divisor; dn_rebuild_zone(dz, old_ht, old_divisor); write_unlock_bh(&dn_fib_tables_lock); kfree(old_ht); } static void dn_free_node(struct dn_fib_node *f) { dn_fib_release_info(DN_FIB_INFO(f)); kmem_cache_free(dn_hash_kmem, f); } static struct dn_zone *dn_new_zone(struct dn_hash *table, int z) { int i; struct dn_zone *dz = kmalloc(sizeof(struct dn_zone), GFP_KERNEL); if (!dz) return NULL; memset(dz, 0, sizeof(struct dn_zone)); if (z) { dz->dz_divisor = 16; dz->dz_hashmask = 0x0F; } else { dz->dz_divisor = 1; dz->dz_hashmask = 0; } dz->dz_hash = kmalloc(dz->dz_divisor*sizeof(struct dn_fib_node *), GFP_KERNEL); if (!dz->dz_hash) { kfree(dz); return NULL; } memset(dz->dz_hash, 0, dz->dz_divisor*sizeof(struct dn_fib_node*)); dz->dz_order = z; dz->dz_mask = dnet_make_mask(z); for(i = z + 1; i <= 16; i++) if (table->dh_zones[i]) break; write_lock_bh(&dn_fib_tables_lock); if (i>16) { dz->dz_next = table->dh_zone_list; table->dh_zone_list = dz; } else { dz->dz_next = table->dh_zones[i]->dz_next; table->dh_zones[i]->dz_next = dz; } table->dh_zones[z] = dz; write_unlock_bh(&dn_fib_tables_lock); return dz; } static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi) { struct rtnexthop *nhp; int nhlen; if (rta->rta_priority && *rta->rta_priority != fi->fib_priority) return 1; if (rta->rta_oif || rta->rta_gw) { if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) && (!rta->rta_gw || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0)) return 0; return 1; } if (rta->rta_mp == NULL) return 0; nhp = RTA_DATA(rta->rta_mp); nhlen = RTA_PAYLOAD(rta->rta_mp); for_nexthops(fi) { int attrlen = nhlen - sizeof(struct rtnexthop); __le16 gw; if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0) return -EINVAL; if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif) return 1; if (attrlen) { gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY); if (gw && gw != nh->nh_gw) return 1; } nhp = RTNH_NEXT(nhp); } endfor_nexthops(fi); return 0; } static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, u8 tb_id, u8 type, u8 scope, void *dst, int dst_len, struct dn_fib_info *fi, unsigned int flags) { struct rtmsg *rtm; struct nlmsghdr *nlh; unsigned char *b = skb->tail; nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags); rtm = NLMSG_DATA(nlh); rtm->rtm_family = AF_DECnet; rtm->rtm_dst_len = dst_len; rtm->rtm_src_len = 0; rtm->rtm_tos = 0; rtm->rtm_table = tb_id; rtm->rtm_flags = fi->fib_flags; rtm->rtm_scope = scope; rtm->rtm_type = type; if (rtm->rtm_dst_len) RTA_PUT(skb, RTA_DST, 2, dst); rtm->rtm_protocol = fi->fib_protocol; if (fi->fib_priority) RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority); if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) goto rtattr_failure; if (fi->fib_nhs == 1) { if (fi->fib_nh->nh_gw) RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw); if (fi->fib_nh->nh_oif) RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif); } if (fi->fib_nhs > 1) { struct rtnexthop *nhp; struct rtattr *mp_head; if (skb_tailroom(skb) <= RTA_SPACE(0)) goto rtattr_failure; mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0)); for_nexthops(fi) { if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4)) goto rtattr_failure; nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp))); nhp->rtnh_flags = nh->nh_flags & 0xFF; nhp->rtnh_hops = nh->nh_weight - 1; nhp->rtnh_ifindex = nh->nh_oif; if (nh->nh_gw) RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw); nhp->rtnh_len = skb->tail - (unsigned char *)nhp; } endfor_nexthops(fi); mp_head->rta_type = RTA_MULTIPATH; mp_head->rta_len = skb->tail - (u8*)mp_head; } nlh->nlmsg_len = skb->tail - b; return skb->len; nlmsg_failure: rtattr_failure: skb_trim(skb, b - skb->data); return -1; } static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id, struct nlmsghdr *nlh, struct netlink_skb_parms *req) { struct sk_buff *skb; u32 pid = req ? req->pid : 0; int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256); skb = alloc_skb(size, GFP_KERNEL); if (!skb) return; if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id, f->fn_type, f->fn_scope, &f->fn_key, z, DN_FIB_INFO(f), 0) < 0) { kfree_skb(skb); return; } NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE; if (nlh->nlmsg_flags & NLM_F_ECHO) atomic_inc(&skb->users); netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL); if (nlh->nlmsg_flags & NLM_F_ECHO) netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT); } static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb, struct dn_fib_table *tb, struct dn_zone *dz, struct dn_fib_node *f) { int i, s_i; s_i = cb->args[3]; for(i = 0; f; i++, f = f->fn_next) { if (i < s_i) continue; if (f->fn_state & DN_S_ZOMBIE) continue; if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, RTM_NEWROUTE, tb->n, (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type, f->fn_scope, &f->fn_key, dz->dz_order, f->fn_info, NLM_F_MULTI) < 0) { cb->args[3] = i; return -1; } } cb->args[3] = i; return skb->len; } static __inline__ int dn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb, struct dn_fib_table *tb, struct dn_zone *dz) { int h, s_h; s_h = cb->args[2]; for(h = 0; h < dz->dz_divisor; h++) { if (h < s_h) continue; if (h > s_h) memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0])); if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL) continue; if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) { cb->args[2] = h; return -1; } } cb->args[2] = h; return skb->len; } static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb) { int m, s_m; struct dn_zone *dz; struct dn_hash *table = (struct dn_hash *)tb->data; s_m = cb->args[1]; read_lock(&dn_fib_tables_lock); for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) { if (m < s_m) continue; if (m > s_m) memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0])); if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) { cb->args[1] = m; read_unlock(&dn_fib_tables_lock); return -1; } } read_unlock(&dn_fib_tables_lock); cb->args[1] = m; return skb->len; } static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req) { struct dn_hash *table = (struct dn_hash *)tb->data; struct dn_fib_node *new_f, *f, **fp, **del_fp; struct dn_zone *dz; struct dn_fib_info *fi; int z = r->rtm_dst_len; int type = r->rtm_type; dn_fib_key_t key; int err; if (z > 16) return -EINVAL; dz = table->dh_zones[z]; if (!dz && !(dz = dn_new_zone(table, z))) return -ENOBUFS; dz_key_0(key); if (rta->rta_dst) { __le16 dst; memcpy(&dst, rta->rta_dst, 2); if (dst & ~DZ_MASK(dz)) return -EINVAL; key = dz_key(dst, dz); } if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL) return err; if (dz->dz_nent > (dz->dz_divisor << 2) && dz->dz_divisor > DN_MAX_DIVISOR && (z==16 || (1<<z) > dz->dz_divisor)) dn_rehash_zone(dz); fp = dn_chain_p(key, dz); DN_FIB_SCAN(f, fp) { if (dn_key_leq(key, f->fn_key)) break; } del_fp = NULL; if (f && (f->fn_state & DN_S_ZOMBIE) && dn_key_eq(f->fn_key, key)) { del_fp = fp; fp = &f->fn_next; f = *fp; goto create; } DN_FIB_SCAN_KEY(f, fp, key) { if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority) break; } if (f && dn_key_eq(f->fn_key, key) && fi->fib_priority == DN_FIB_INFO(f)->fib_priority) { struct dn_fib_node **ins_fp; err = -EEXIST; if (n->nlmsg_flags & NLM_F_EXCL) goto out; if (n->nlmsg_flags & NLM_F_REPLACE) { del_fp = fp; fp = &f->fn_next; f = *fp; goto replace; } ins_fp = fp; err = -EEXIST; DN_FIB_SCAN_KEY(f, fp, key) { if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority) break; if (f->fn_type == type && f->fn_scope == r->rtm_scope && DN_FIB_INFO(f) == fi) goto out; } if (!(n->nlmsg_flags & NLM_F_APPEND)) { fp = ins_fp; f = *fp; } } create: err = -ENOENT; if (!(n->nlmsg_flags & NLM_F_CREATE)) goto out; replace: err = -ENOBUFS; new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL); if (new_f == NULL) goto out; memset(new_f, 0, sizeof(struct dn_fib_node)); new_f->fn_key = key; new_f->fn_type = type; new_f->fn_scope = r->rtm_scope; DN_FIB_INFO(new_f) = fi; new_f->fn_next = f; write_lock_bh(&dn_fib_tables_lock); *fp = new_f; write_unlock_bh(&dn_fib_tables_lock); dz->dz_nent++; if (del_fp) { f = *del_fp; write_lock_bh(&dn_fib_tables_lock); *del_fp = f->fn_next; write_unlock_bh(&dn_fib_tables_lock); if (!(f->fn_state & DN_S_ZOMBIE)) dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req); if (f->fn_state & DN_S_ACCESSED) dn_rt_cache_flush(-1); dn_free_node(f); dz->dz_nent--; } else { dn_rt_cache_flush(-1); } dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req); return 0; out: dn_fib_release_info(fi); return err; } static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req) { struct dn_hash *table = (struct dn_hash*)tb->data; struct dn_fib_node **fp, **del_fp, *f; int z = r->rtm_dst_len; struct dn_zone *dz; dn_fib_key_t key; int matched; if (z > 16) return -EINVAL; if ((dz = table->dh_zones[z]) == NULL) return -ESRCH; dz_key_0(key); if (rta->rta_dst) { __le16 dst; memcpy(&dst, rta->rta_dst, 2); if (dst & ~DZ_MASK(dz)) return -EINVAL; key = dz_key(dst, dz); } fp = dn_chain_p(key, dz); DN_FIB_SCAN(f, fp) { if (dn_key_eq(f->fn_key, key)) break; if (dn_key_leq(key, f->fn_key)) return -ESRCH; } matched = 0; del_fp = NULL; DN_FIB_SCAN_KEY(f, fp, key) { struct dn_fib_info *fi = DN_FIB_INFO(f); if (f->fn_state & DN_S_ZOMBIE) return -ESRCH; matched++; if (del_fp == NULL && (!r->rtm_type || f->fn_type == r->rtm_type) && (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) && (!r->rtm_protocol || fi->fib_protocol == r->rtm_protocol) && dn_fib_nh_match(r, n, rta, fi) == 0) del_fp = fp; } if (del_fp) { f = *del_fp; dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req); if (matched != 1) { write_lock_bh(&dn_fib_tables_lock); *del_fp = f->fn_next; write_unlock_bh(&dn_fib_tables_lock); if (f->fn_state & DN_S_ACCESSED) dn_rt_cache_flush(-1); dn_free_node(f); dz->dz_nent--; } else { f->fn_state |= DN_S_ZOMBIE; if (f->fn_state & DN_S_ACCESSED) { f->fn_state &= ~DN_S_ACCESSED; dn_rt_cache_flush(-1); } if (++dn_fib_hash_zombies > 128) dn_fib_flush(); } return 0; } return -ESRCH; } static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table) { int found = 0; struct dn_fib_node *f; while((f = *fp) != NULL) { struct dn_fib_info *fi = DN_FIB_INFO(f); if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) { write_lock_bh(&dn_fib_tables_lock); *fp = f->fn_next; write_unlock_bh(&dn_fib_tables_lock); dn_free_node(f); found++; continue; } fp = &f->fn_next; } return found; } static int dn_fib_table_flush(struct dn_fib_table *tb) { struct dn_hash *table = (struct dn_hash *)tb->data; struct dn_zone *dz; int found = 0; dn_fib_hash_zombies = 0; for(dz = table->dh_zone_list; dz; dz = dz->dz_next) { int i; int tmp = 0; for(i = dz->dz_divisor-1; i >= 0; i--) tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table); dz->dz_nent -= tmp; found += tmp; } return found; } static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res) { int err; struct dn_zone *dz; struct dn_hash *t = (struct dn_hash *)tb->data; read_lock(&dn_fib_tables_lock); for(dz = t->dh_zone_list; dz; dz = dz->dz_next) { struct dn_fib_node *f; dn_fib_key_t k = dz_key(flp->fld_dst, dz); for(f = dz_chain(k, dz); f; f = f->fn_next) { if (!dn_key_eq(k, f->fn_key)) { if (dn_key_leq(k, f->fn_key)) break; else continue; } f->fn_state |= DN_S_ACCESSED; if (f->fn_state&DN_S_ZOMBIE) continue; if (f->fn_scope < flp->fld_scope) continue; err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res); if (err == 0) { res->type = f->fn_type; res->scope = f->fn_scope; res->prefixlen = dz->dz_order; goto out; } if (err < 0) goto out; } } err = 1; out: read_unlock(&dn_fib_tables_lock); return err; } struct dn_fib_table *dn_fib_get_table(int n, int create) { struct dn_fib_table *t; if (n < RT_TABLE_MIN) return NULL; if (n > RT_TABLE_MAX) return NULL; if (dn_fib_tables[n]) return dn_fib_tables[n]; if (!create) return NULL; if (in_interrupt() && net_ratelimit()) { printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n"); return NULL; } if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL) return NULL; memset(t, 0, sizeof(struct dn_fib_table)); t->n = n; t->insert = dn_fib_table_insert; t->delete = dn_fib_table_delete; t->lookup = dn_fib_table_lookup; t->flush = dn_fib_table_flush; t->dump = dn_fib_table_dump; memset(t->data, 0, sizeof(struct dn_hash)); dn_fib_tables[n] = t; return t; } static void dn_fib_del_tree(int n) { struct dn_fib_table *t; write_lock(&dn_fib_tables_lock); t = dn_fib_tables[n]; dn_fib_tables[n] = NULL; write_unlock(&dn_fib_tables_lock); kfree(t); } struct dn_fib_table *dn_fib_empty_table(void) { int id; for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++) if (dn_fib_tables[id] == NULL) return dn_fib_get_table(id, 1); return NULL; } void __init dn_fib_table_init(void) { dn_hash_kmem = kmem_cache_create("dn_fib_info_cache", sizeof(struct dn_fib_info), 0, SLAB_HWCACHE_ALIGN, NULL, NULL); } void __exit dn_fib_table_cleanup(void) { int i; for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i) dn_fib_del_tree(i); return; }